Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2017-18903

26
FAUCET Score

CVE-2017-18903 describes a Cross-Site Request Forgery (CSRF) vulnerability affecting Mattermost Server versions prior to 4.0.0, 3.10.2, and 3.9.2, specifically when Cross-Origin Resource Sharing (CORS) is enabled. This vulnerability carries a high CVSS score of 8.8, indicating a critical risk due to its network-based attack vector, low attack complexity, and potential for high impact on confidentiality, integrity, and availability. While the vulnerability has a low EPSS score and is not listed in CISA's KEV catalog, there is no public exploit code available (e.g., Metasploit, Nuclei, ExploitDB), and community discussion and media coverage are minimal, suggesting it is not actively exploited in the wild.

Impacted Technologies

VendorProductVersion(s)CPE
< 3.9.2CPE matchmatch criteria
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
>= 3.10.0, < 3.10.2CPE matchmatch criteria
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
2.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.43%
Probability of exploitation in next 30 days
EPSS Percentile
35.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0043 is in the 38th percentile among its peer group of 14,855 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.1 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (2)

gopatch availablevia ghsa
Product: github.com/mattermost/mattermost-serverFixed in: 3.9.2
gopatch availablevia ghsa
Product: github.com/mattermost/mattermost-serverFixed in: 3.10.2

Vendor Advisories (1)

goGHSA-fcwg-45jh-5qhfhigh

Mattermost Server vulnerable to CSRF if CORS is enabled

May 24, 2022

References

mattermost.com / security-updates
Vendor Advisory